Mercurial > hg > nginx-quic
view src/core/ngx_hash.h @ 4385:70ba81827472
Cache locks initial implementation.
New directives: proxy_cache_lock on/off, proxy_cache_lock_timeout. With
proxy_cache_lock set to on, only one request will be allowed to go to
upstream for a particular cache item. Others will wait for a response
to appear in cache (or cache lock released) up to proxy_cache_lock_timeout.
Waiting requests will recheck if they have cached response ready (or are
allowed to run) every 500ms.
Note: we intentionally don't intercept NGX_DECLINED possibly returned by
ngx_http_file_cache_read(). This needs more work (possibly safe, but needs
further investigation). Anyway, it's exceptional situation.
Note: probably there should be a way to disable caching of responses
if there is already one request fetching resource to cache (without waiting
at all). Two possible ways include another cache lock option ("no_cache")
or using proxy_no_cache with some supplied variable.
Note: probably there should be a way to lock updating requests as well. For
now "proxy_cache_use_stale updating" is available.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 26 Dec 2011 11:15:23 +0000 |
parents | 4c70bbdfd076 |
children | d620f497c50f |
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/* * Copyright (C) Igor Sysoev */ #ifndef _NGX_HASH_H_INCLUDED_ #define _NGX_HASH_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> typedef struct { void *value; u_short len; u_char name[1]; } ngx_hash_elt_t; typedef struct { ngx_hash_elt_t **buckets; ngx_uint_t size; } ngx_hash_t; typedef struct { ngx_hash_t hash; void *value; } ngx_hash_wildcard_t; typedef struct { ngx_str_t key; ngx_uint_t key_hash; void *value; } ngx_hash_key_t; typedef ngx_uint_t (*ngx_hash_key_pt) (u_char *data, size_t len); typedef struct { ngx_hash_t hash; ngx_hash_wildcard_t *wc_head; ngx_hash_wildcard_t *wc_tail; } ngx_hash_combined_t; typedef struct { ngx_hash_t *hash; ngx_hash_key_pt key; ngx_uint_t max_size; ngx_uint_t bucket_size; char *name; ngx_pool_t *pool; ngx_pool_t *temp_pool; } ngx_hash_init_t; #define NGX_HASH_SMALL 1 #define NGX_HASH_LARGE 2 #define NGX_HASH_LARGE_ASIZE 16384 #define NGX_HASH_LARGE_HSIZE 10007 #define NGX_HASH_WILDCARD_KEY 1 #define NGX_HASH_READONLY_KEY 2 typedef struct { ngx_uint_t hsize; ngx_pool_t *pool; ngx_pool_t *temp_pool; ngx_array_t keys; ngx_array_t *keys_hash; ngx_array_t dns_wc_head; ngx_array_t *dns_wc_head_hash; ngx_array_t dns_wc_tail; ngx_array_t *dns_wc_tail_hash; } ngx_hash_keys_arrays_t; typedef struct { ngx_uint_t hash; ngx_str_t key; ngx_str_t value; u_char *lowcase_key; } ngx_table_elt_t; void *ngx_hash_find(ngx_hash_t *hash, ngx_uint_t key, u_char *name, size_t len); void *ngx_hash_find_wc_head(ngx_hash_wildcard_t *hwc, u_char *name, size_t len); void *ngx_hash_find_wc_tail(ngx_hash_wildcard_t *hwc, u_char *name, size_t len); void *ngx_hash_find_combined(ngx_hash_combined_t *hash, ngx_uint_t key, u_char *name, size_t len); ngx_int_t ngx_hash_init(ngx_hash_init_t *hinit, ngx_hash_key_t *names, ngx_uint_t nelts); ngx_int_t ngx_hash_wildcard_init(ngx_hash_init_t *hinit, ngx_hash_key_t *names, ngx_uint_t nelts); #define ngx_hash(key, c) ((ngx_uint_t) key * 31 + c) ngx_uint_t ngx_hash_key(u_char *data, size_t len); ngx_uint_t ngx_hash_key_lc(u_char *data, size_t len); ngx_uint_t ngx_hash_strlow(u_char *dst, u_char *src, size_t n); ngx_int_t ngx_hash_keys_array_init(ngx_hash_keys_arrays_t *ha, ngx_uint_t type); ngx_int_t ngx_hash_add_key(ngx_hash_keys_arrays_t *ha, ngx_str_t *key, void *value, ngx_uint_t flags); #endif /* _NGX_HASH_H_INCLUDED_ */